Australian hybrid fish story – Media jumps the shark

Pretty much everyone who has seen this today shakes their head and wonders. I’m wondering too. First, the story which is being serially regurgitated without any thought in media outlets world wide:

Please read this excepted text from the story carefully:

In what is being hailed as the world’s first evidence of inter-species breeding among sharks, a team of marine researchers at the University of Queensland have identified 57 hybrid sharks in waters off Australia‘s east coast.

…

Ovenden speculated that the two species began mating in response to environmental change, as the hybrid blacktips are able to travel further south to cooler waters than the Australian blacktips. The team is looking into climate change and human fishing, among other potential triggers.

Pretty clear with the headline, right? There’s more examples of this, such as this one from the Business Insider which takes the cake:

World-first discovery of hybrid sharks off Australia’s east coast

A group of leading marine scientists has discovered that sharks on Australia’s east coast display a mysterious tendency to interbreed, challenging several accepted scientific theories regarding shark behaviour.

In a joint-UQ research project, scientists have discovered widespread hybridisation in the wild between two shark species commonly caught in Australia’s east coast shark fisheries.

The Australian black tip shark (Carcharhinus tilstoni) and the common black tip shark (C. limbatus) have overlapping distributions along the northern and eastern Australian coastline.

Using both genetic testing and body measurements, 57 hybrid animals were identified from five locations, spanning 2000km from northern NSW to far northern Queensland. Although closely related, the two species grow to different maximum sizes and are genetically distinct.

Dr Jennifer Ovenden, an expert in genetics of fisheries species and a member of the scientific team said this was the first discovery of sharks hybridising and it flagged a warning that other closely related shark and ray species around the world may be doing the same thing.

“Wild hybrids are usually hard to find, so detecting hybrids and their offspring is extraordinary,” Dr Ovenden said.

“To find 57 hybrids along 2000km of coastline is unprecedented.

“Hybridisation could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north.

“While the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline.”

Scientists from The University of Queensland, James Cook University’s Fishing and Fisheries Research Centre, the Queensland Department of Employment, Economic Development and Innovation and the New South Wales Department of Primary Industries are now investigating the full extent of the hybrid zone and are attempting to measure hybrid fitness.

The research, co-funded by the Fisheries Research and Development Corporation, identified a mismatch between species identification using mitochondrial DNA sequence and species identification using morphological characters (length at sexual maturity, length at birth and number of vertebrae).

A nuclear DNA marker (inherited from both parents) was sequenced to confirm the hybrid status.

Dr Colin Simpfendorfer from James Cook University’s Fishing and Fisheries Research Centre said black tip sharks were one of the most studied species in tropical Australia.

“The results of this research show that we still have a lot to learn about these important ocean predators,” he said.

“Hybridisation could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north.

“While the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline.”

So “environmental change” gets morphed into a “global warming” headline, when clearly, environmental change could be any number of things; pollution, changes in food supply, overfishing, competition, any of these (and others we don’t know about) could be factors…but “global warming” is automatically looked upon as the culprit. WUWT?

So, lets look at temperature. I asked Bob Tisdale to supply some sea temperature maps and graphs for the area. First the current available SST for Australia:

So much for the idea that the water is cooler to the southeast, and least in November. The waters of the south appear to be warming faster according to this anomaly map.

Here’s the last thirty years of sea surface temperatures from the area:

Less discerning reporters would immediately go A-Ha! The smoking gun, sea surface temperatures went up. Yes they did, and the trend is 0.135 °C/decade, and the trend line suggests Australian coastal sea temperature has increased by 0.45°C over thirty years.

But, in the last ten years (denoted by the span of the blue line) the temperatures have been pretty much flat.

Consider these points then:

1. Would you believe that one of the oldest creatures on Earth, which have managed to survive 500 million years over all sorts of temperature global temperature swings far greater, is sensitive to SST changes of 0.15 degree per decade enough to go on a panic breeding frenzy to save itself?

This figure shows the long-term evolution of oxygen isotope ratios during the Phanerozoic eon as measured in fossils, reported by Veizer et al. (1999), and updated online in 2004 - click for more

2. Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago. In this paper, the maximum lifespan of the Australian black tip shark (Carcharhinus tilstoni) is given:

The greatest recorded ages for C. tilstoni were 12 years for females and 8 years for males…

So clearly, this new hybrid is a recent decadal scale development, and the last ten years of temperature in the area have been essentially flat. Connecting this with “global warming” doesn’t wash.

3. Ok, back to the “speculation” part of the headline:

Ovenden speculated that the two species began mating in response to environmental change, as the hybrid blacktips are able to travel further south to cooler waters than the Australian blacktips. The team is looking into climate change and human fishing, among other potential triggers.

It seems the Blacktip Shark isn’t confined in range at all, as this 2010 paper shows (bolding mine):

Genetic data show that Carcharhinus tilstoni is not confined to the tropics, highlighting the importance of a multifaceted approach to species identification

Boomer, J.J., Peddemors, V. and Stow, A.J., 2010. Genetic data show that Carcharhinus tilstoni is not confined to the tropics, highlighting the importance of a multifaceted approach to species identification. Journal of Fish Biology, 77:1165–1172.

Summary

Sharks are prone to human-induced impacts, including fishing, habitat destruction and pollution. Therefore, effective conservation and management requires knowledge of species distributions. Despite the size and notoriety of sharks, distributions of some species remain uncertain due to limited opportunities for observation or difficulties with species identification.

One of the most difficult groups of sharks to identify correctly is the ‘blacktip sharks’. This group of whaler sharks are harvested in substantial numbers along the Australian east coast, including NSW, yet little is known of their distribution and resultant potential portion of the commercial shark catch.

The NSW Shark Meshing Program (SMP) research has collected genetic samples from most sharks caught for many years. Analysis of these samples to determine proportions of each species caught in the shark nets yielded the surprising discovery that the tropical Australian blacktip shark (Carcharhinus tilstoni) was regularly represented. Approximately one-third of the ‘blacktip sharks’ previously assigned to the common blacktip (C. limbatus) were identified as Australian blacktip sharks. This discovery extends the range of this tropical species over 1000km southwards into temperate waters off Sydney.

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Really, I worry for the sane future of Australia, I just rolled my eyes when I read this. We were once called to be the lucky country, seems to be devolving into the dumbest country and rapidly too!
From the article;
“In what is being hailed as the world’s first evidence of inter-species breeding among sharks,…”
Well, anyone who knows the slightest thing about DNA would know that would not be possible without help from a geneticist. Now, I KNOW there is somthing called inter-species CLONING.

@ Patrick Davis
Without wanting to claim more than a layman’s knowledge of DNA, I nevertheless have to point out that there’s more to the issue than you covered.
The simple definition of ‘species’ as ‘populations that don’t interbreed’ is a useful generalisation. According to that definition, this would indeed be impossible. But the definition is not completely accurate. For example there are some people who can’t reproduce with some other people, but we’re all still the same species. Likewise, there are some groups of sharks that wouldn’t normally interbreed, being territorially isolated (though with all the caveats introduced by their being marine creatures) and possessing slightly different characteristics. Generally we call these different species, but it can be possible for some individuals within these populations to interbreed with some individuals within the other populations.
I admit that I haven’t heard of inter species CLONING. Possibly you are thinking of chimeras formed by genetic manipulation? Could you give me a link to the article you’re thinking of?
Regards.

The way it was written it gave the impression that the sharks detected the ‘global’ warming, worked out what that would mean in the future and decided upon a cross breeding strategy to deal with the effects of global warming. Not bad eh!

Oh, the scandal. Ozzies have been killing off their local sharks for years with nets. Now the trash “common” sharks from across the tracks up North have moved into the largely abandoned shark settlements and are having their way with the remaining “ozzie” sharks. Oh, the humiliation.
Rumors of miscegenation are widespread. Fears of a spread of hybridization to the general Ozzie population have reached the highest levels of government. Plans dating back to the 50’s for mass sterilization are again being dusted off and circulated. Leaked documents suggest Prime Minister Gillard, in a valiant effort to save the nation will announce a condom tax in the near future with condom offsets to be mailed to every household. A nervous world watches to see if Oz will survive.

“Leo Morgan says:
January 4, 2012 at 1:18 am”
Nope! DNA is removed from the “nearest” related species donor egg, then DNA from ANOTHER species is inserted. The resultant offspring is in the form of the species from the inserted DNA. Example, endangered wild African cats (Not Lions, Tigers etc). Ineter-breeding has been tried and failed. So an egg from a domestic cat is “cleaned” of its DNA. The DNA of the wild African cat is inserted. The offspring are, genetically pure, wild African cats, which can themselves breed to produce pure genetic offspring. This technique is relatively new, and is likely to be used to “protect” endangered species.

I have met plenty of sharks, in the surf, off the east coast of Australia. On many occasions. In all seasons and conditions.
They are very talkative. All of them.
Basically, what emerges from even the most casual conversation with the most socially reserved of shark, is that all Australian sharks will f#*k anything that comes their way.
It’s just how they’ve been raised. An artefact of a libidionous local culture. Very Australian, in fact.
They all say the same thing, in their sharky-boy kinda way.
Therefore, it is probably not down to global warming …

These sharks aren’t even different species, they are simply different varieties of the same species. Using their logic, should a European Caucasian man marry a Japanese Asian woman, we would have some environmental crisis induced inter-species … something … going on.
Give me a break.

The suspected ’cause’ of this — greater adaptability of the hybrid species to temperature variations — could equally be attributed to global cooling as to global warming.
Whatever this is about, it sure ain’t science.

ferd berple says:
January 4, 2012 at 1:10 am
News flash. Genetic testing proves climate scientists have been secretly breeding with morons. Results shown a rapid decrease in the IQ of morons. Full story at 11.
=============
🙂 summed up nicely Fred..
must be near re funding time at QUT…
whats the old line
proximity breeds propinquity?
all sharks probably look the same in the dark;-)
and
if theyve just managed to dna test and find 57, who’s to say that they havent been crossing for ever?

Whoa there, bor. While the articles clearly show the illiteracy of at least some sections of the press, you seem to have a couple of misconceptions yourself. For instance: “So much for the idea that the water is cooler to the SouthEast, and [at?] least in November.” The chart shows temperature anomalies, so it’s entirely probable that the water temperature is considerably cooler off NSW, despite having warmed recently.
Secondly, “Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago.” Non sequitur! It is a recent observation entirely because the genetic sequencing necessary to make it has only been available recently. Quite likely there have always been Common/Australian hybrids in the shared parts of their ranges, but no-one knew.
Patrick Davis neatly illustrates Alexander Pope’s dictum about a little learning. While I’m quite sure that “anyone who knows the slightest thing about DNA would know that would not be possible without help from a geneticist.”, anyone with rather deeper knowledge is aware that many species have been re-hybridising for millennia with not a geneticist in sight. Ducks are perhaps the best example among higher animals – they’ll cross-breed between genera at the drop of a hat. Leo Morgan has it right – our definition of species as groups of similar individuals that cannot cross-breed to produce viable offspring is really only a marginally useful distinction for basic biology. Ducks have been mentioned, but when you come to plants the whole thing is a hopeless mess

Certainly must be the biggest global warming beat up of 2012 SO FAR (lots more to come).
In this ABC radio interview the interviewer tries hard with the researcher from the University of Queensland but cannot get anywhere nears the right answer:http://www.radioaustralia.net.au/pacbeat/stories/201201/s3402143.htmINTERVIEWER BRIAN ABBOTT: The fact that you have a warm tropical water shark interbreeding with a cooler temperate water shark. Does this mean perhaps fish in the sea, other sharks could adapt to the heating waters caused by climate change?DR JESS MORGAN University of Queensland: For the temperate species shark its quite unusual. It also will occur in tropical waters. It’s got a very wide distribution. What we have seen with this particular group is that our tropical species when it is a hybrid has moved South, has moved into cooler waters, so it has made it possible for a species that would normally be restricted to the tropics to expand its range. So we don’t think that climate change has driven that hybridisation event, but it does look like the hybrids would be best in different temperature waters than their parents’ species alone.
Come on, these sharks are very closely related that even fishermen cannot tell them apart and the only way scientists can do it is to dissect them and count the number of vertebrae. No wonder the poor old sharks started screwing up. Also, in evolution hasn’t everything in Nature, except European Royal families, worked out that hybrid vigour produces stronger offspring?
God help us, they will be demanding research funds now to count grolar bears.
Actually I think the reason the black tipped shark crossed the Great Barrier Reef was that he was tired of swimming in circles and he wanted to get to the other tide – groan.

I think you are being much too simplistic in your debunking. When we say global warming is happening, we don’t just mean that temperatures are rising, since the current rise is within natural bounds. Rather, there is an ongoing process of CO2 causing the planet to keep in more heat and the planet warms over decades and even centuries. So even if temperatures have stabilized in the last decade, global warming is still happening, and it will be much warmer in the future. These sharks have adapted to this global warming, and are positioning themselves for a warmer world of the future.
Sharks are known to be very intelligent creatures. Particularly in Australia, the home country of golfer Greg Norman, who was nicknamed The Shark.

I look forward to the researchers placing a rebuttal notice in prominent news outlets regarding the words the did not say (global warming, climate change, etc).
“The results of this research show that we still have a lot to learn about these important ocean predators,” he said. More funds, please.

@Leo Morgan January 4, 2012 at 1:18 am
“For example there are some people who can’t reproduce with some other people, but we’re all still the same species.”
Could you elaborate?
Interspecies cloning is widespread in plants – the rose family is a good example. It is not necessarily used because a hybrid is sterile, but to propagate a desirable individual plant as a commercial variety. The technique is so commonplace in plants that it seems hardly worth mention, and the term is mostly applied to work on animals (including humans), where there is interspecies cloning perpetrated – legally and illegally – in labs all over the world.

“Ovenden speculated that the two species began mating in response to environmental change, as the hybrid blacktips are able to travel further south to cooler waters than the Australian blacktips. The team is looking into climate change and human fishing, among other potential triggers.”
This statement doesn’t make any sense. If the reason the sharks are hybridizing is because of “climate change” (warming waters), why would Australian blacktips want to mate with the common blacktips whose natural habitat is cooler waters?
The “Business Insider” article was no better. “According to lead researcher Jess Morgan, the hybridization might be a sign that the animals are adapting to rising temperature levels as a result of climate change.” “While the Australian black-tip lives in tropical waters, the new breed was found in cooler waters 2,000 kilometers down the coast. In essence, interbreeding has allowed the shark to survive in temperate waters.”
Again, if the problem is climate change (warming), why would the sharks interbreed so they could survive in temperate waters?
The logic (or illogic) seems to be that the tropical waters are getting too hot, so the sharks must interbreed so they can cool off. However, it seems to me, if I were a shark and found the waters were getting too warm where I currently lived, I’d simply swim a little further south until I found waters more to my liking. Why go through all the trouble of interbreeding just so I can survive in cool temperate waters when, if CAGW is to be believed, those temperate waters will soon become tropical?!

Shark = flake = fish and chips. No matter what breed they are they all taste pretty bloody good to me.
So an overlap in population causes hybrids?
Who would have thought that would happen in Australia?
You might also be equally gob smacked (or not) at the ‘hybrid’ dingos which have been crossbreading with domestic dogs for teh past 100 years or so, but of course that hasn’t got anything to do with AGW now does it?

I particularly love the headline saying “another scary sign that global warming is real”. That hysteria worked for a few years. Now Joe Public just skims the headline, realises it’s only more climate change BS, and moves on to a more interesting story, like Lindsay Lohan’s playboy pics (males), or Jennifer Aniston’s latest heartbreak (females). The actress bumph, straight from the PR agent’s office, is more “real” than the climate change freak-show. And every new “scary” headline just pushes the public further away. So come on WWF and Greenpeace, keep the scary headlines coming …

Oh dear. Isn’t there some trivial pursuit data dredged up from somewhere about the difference in DNA between men & women is infinitessimal? Hardly surprising as all foetus are inherently female as men have nipples. Isn’t there the same said about DNA for humans & apes, etc? All goes back to the hole in the ozone layer, just because we found it how do we not know it hasn’t always been there? Genetically we must have some shark genes in us all somewhere!

I heard this story on the 6 O’clock ABC Evening News Program. It sounded absurd, but Diane Sawyer read it as though there was no doubt about it at all. Somebody was pimping this story. It would be interesting to find out exactly who it was.

“Species” is a human attempt at classification. It is not infallible !!!
Basically if two “species” are capable of interbreeding and can matched pairs of chomosones, (as these sharks obviously can) then a fertile offspring “may” be possible. A horse and a donkey are physically capable of interbreeding, but have a chomosone mismatch, and the offspring is therefore infertile.
In the case of these sharks, a probable ‘better’ definition might be that they are similar sub-species, since they are obviously able to interbreed.

While the news coverage was definitely a case of unfounded warmist rubbish, I’d like to point out that the northern waters of Australia are definitely much warmer than the southern waters, pretty much on a year round basis.
I think the map you have included of sea temps is a temperature anomaly map, which shouws you how the temperature at any point compares with the average temperature at that same location. It is not comparing northern temps to southern temps.

Why don’t we all mind our own business. If animals can interbreed, let them do it, it has to be a natural occurrence or it wouldn’t work. Our arrogance in making arbitrary divisions as to species, leads to upset (of some people) when said species don’t adhere to The Rules. Look at the panic over red-headed ducks and white-headed ducks inter-breeding Kill/cull the redheads to save the whiteheads! Species are sacrosant! No. they aren’t, it’s just an accounting convenience.
Anthea

“Hybridisation could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north.”
Interesting, seems to imply it could be ‘good for the species’, one of those non-scientific ways of thinking that people find it hard to avoid. Hybridization between related species is very common when they overlap. Eastern and Pale-headed Rosellas, for example, hybridize where they overlap in distribution in southern Queensland and this has been known for many years. Nothing at all to do with climate change as far as I can see.

If two individuals are able to breed and the offspring are fertile then, by definition, they are the same species.
So these sharks are actually the same species and this illustrates a problem in biology. In the quest to put on display the diversity and fecundity of life biologists have invented millions of species without any rigorous test to see if they’re really different species or members of the same species who for one reason or another are not known to interbreed. It’s also deeply connected with environmental whackos. You see, if something happens so that one of these shark breeds were to disappear, the environmental whackos could claim that another species was lost. Or if there were a few of those sharks left they could be placed on the endangered species list.
If we didn’t know better there would be a thousand different species of dogs, for instance. Or under the loose definition commonly used today Eskimos would be a different species from Jamaicans. It’s ridiculous and is what happens when science is compromised by rent seekers and political agendas.

If the two sub-species are so closely related genetically, I can’t believe they just started straying now. I think it is a matter of not really caring in the past but now even sharks get caught in the media spotlight when inter-bedroom gymnastics are engaged in. The media, all of it, has sunken to the three most important attention grabbers at one time loved only by the Enquirer. Sex, blood, and climate Armageddon. Not even aliens compete with that anymore.

The article is an example of real science turned into junk science. The Queensland press release stated what had been observed. The news stories then turned it into junk science. I looked for indications the hybrids were mules, but found none. That is an important question to answer. If they are mules, then this may be the first OBSERVED incident, but not the first incident as it may be a common cyclical thing when El Nino and La Nina get running as they have over the past 10 years. But since they hybrids are mules, when things calm down, the mules die out, and they hybrids disappear.
These are questions that they real scientists at Queensland are probably asking and investigating. However, the junk science of the media hysteria will not allow such questions to be put forward since they have nothing to do with the agenda, and indeed, may negatively impact their junk science.

Nevertheless, as we know (because the Liberals told us so) thousands upon thousands upon thousands of scientists disagree with you Anthony. Therefore – just to be on the safe side – we should be very scared of this, ahem, story, and sacrifice billions of dollars to the Kyoto Gods.
I don’t really need to add a “/sarc” do I?

“Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago.”
True that they are a recent observation, but perhaps it’s only because they started looking for this recently. Interbreeding among closely related species is quite common.
I suspect that this has been going on for quite a long time. Our tendency for hubris explains why we think it “just happened recently.”

Isn’t shark interbreeding more a function of the avaialbility of breeding mates rather than evidence of CAGW? Perhaps interbreeding is what sharks do when their populations are reduced.
Of course, I forgot, everything is due to CAGW. Sorry , how could I have been so foolish.

“The results of this research show that we still have a lot to learn about these important ocean predators,” he said.
—————————————————————–
I’ve never heard of a study concluding that before.
And shouldn’t it be shark “jumps the Fonz” in this case?

I love the whopper analogy Anthony ha ha ha! Media ‘jumping the shark’ for sure! Hysterical.
They seemed to have missed the angle which suggests that presence of hybrids means that they’re not actually derived from distinct species. Distinct species are unable to reproduce with each other and produce ongoing bloodlines (think horse + donkey = mule).
The researchers got caught in an ‘oops’ moment and now have to say ‘gee, I guess length, fin color and number of vertebrate aren’t a sufficient basis to define a species’.

My interpretation of the recency of inter-species breeding is that it probably has been just as common in the past, but between no one looking for it, and the changes in the technology of DNA testing, that it has only been noticed recently. These 2 sharks are closely related and it may be that in the areas where they both live, they have always at least slightly hybridized. If the hybrids are not fertile, then the population of hybrids will not increase like a normal population–there will just be a few of these anomalies around.

the world’s first evidence of inter-species breeding among sharks
If successful “inter-species breeding” is well known among non-sharks, what’s the big deal here?the two species…are genetically distinct.
Almost every human being is “genetically distinct” from every other one. So what? But, then again, we also have ~77% the same genes as Fruit Flies, so that kind of interbreeding would really be a “first”.“Hybridisation could enable the sharks to adapt to environmental change as the smaller Australian black tip currently favours tropical waters in the north.
“While the larger common black tip is more abundant in sub-tropical and temperate waters along the south-eastern Australian coastline.”
Therefore, possibly helping both kinds to adapt to possibly slightly different niches? My my, isn’t it amazing how “hybridization” works in the course of life’s continuous evolutionary attempts to “adapt to environmental change“, or doesn’t – a more “successful” outcome perhaps being in relation to a changed or expanded “ecological niche” for whatever reason?Scientists….are attempting to measure hybrid fitness.
So, now, instead of leaving the hybrids alone with Nature, finding out more about what’s already known about Black Tip sharks like Anthony did, thinking about other possible factors producing this “first” in that geographical area, and also simply looking at catches over a period of some years later, the “group of leading marine scientists” are probably going to “help” the hybrids by capturing some of them, doing “scientific” tests under some kind of anesthesia, then probably finish up by putting radio transmitter nose or lip rings in certain lucky individuals, after the manner of “scientists” banding Penguin flippers, to see how they fare?

Patrick Davis says:
January 4, 2012 at 12:46 am
“…Well, anyone who knows the slightest thing about DNA would know that would not be possible without help from a geneticist. Now, I KNOW there is somthing [sic] called inter-species CLONING.”
Ummm….not exactly. In many closely related species, especially those with overlapping ranges, hybridization happens occasionally. As a group, the southern (US) pines (loblolly, shortleaf, slash, longleaf, e.g.) are one good example.
While not considered to be a primary cause, occasional hybridization between recognized species, is a factor in long term speciation.

“2. Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago.”
No, sorry, it only stands to reason that such hybrids have not been observed 10 or 20 years ago.
It does not mean there weren’t any hybrids.
Dr Ovenden says they are difficult to observe in the wild, and they are certainly more difficult to observe in the wild if there’s no funding for such observations! The advances in research technologies like in DNA analysis during the last years probably also played a role here.
Hybrids are of great interest to biologists, and have been studied for some time, see here:http://en.wikipedia.org/wiki/Hybrid_zone
Unlike Mytilus, the example given in the wiki article, sharks are not sitting around on rocky shores, so establishing a hybrid zone is of course enormously difficult, but it doesn’t mean it doesn’t exist.
This find is hugely interesting, especially when shorn of the usual climate hype by the MSM.

I chuckled at Delingpole’s take, but you win this one. Thanks for the thorough research and analysis! (I failed to find the original release with my quick search after seeing the story regurgitated on Fox.)
I found the following statement particularly informative regarding range limits due to climate and the potential impetuous of warming mattering to these critters mating habits: “…have overlapping distributions along the northern and eastern Australian coastline.” It seems that both already like the climate. Thus, not a justification for interbreeding. I suspect the simple instinct to mate and hormones (however they apply to sharks).
I also note the emphasis on similarity between these two species. It would seem that before DNA testing was common, this hybrid would have necessarily gone unnoticed. It seems unlikely that it is a new phenomenon, we can simply detect it now.

Interesting detail about the Australian black tip and the common blacktip , they are physically identical except for the number of vertebrae , 174–182 vertebrae in the Australian BT and 182–203 in the common BT so as fishermen rarely count the vertebrae or check the genetic markers of their catch , Australians may well have been dining on hybrid blacktip flake since European settlement and no one would know . I don`t know how the Aborigines at the time were at shark hunting/fishing but given their admirable proficiency at turning anything else that hops , crawls, swims or paddles into a feed there exists the possibility that Australians may have been eating hybrid shark from BEFORE european settlement .

Oh oh, it’s beginning to look like “hybridization” as a result of “environmental change” is gearing up the Sharks worldwide to be able to take out the last of the Polar Bears by 2100. Nat Geo has yet to weigh in regarding the catastrophic effect on the Big Cats as well, but since we already know it “could” happen, that’s all we need to know – pending only a critical grant for a NAS related “study”.

Based on the ‘jump-the-shark-headlines’, I have to wonder why have I never seen:
“Inter Racial Marriages – Proof of Global Warming”
From a historical perspective: Anthropologists have noted that when societies tend to expand allowing people to intermingle more with other societies – thus more potential inter-race children, the planet has been warmer. Conversely, when societies tend to pull back and keep to themselves with people intermingling less – thus less potential inter-race children, the planet has been colder.
Similar to CO2, inter-race children is a driving force on the global climate. This can most easily be seen due to the ease of travel over the recent past. With the speed of inter-continental travel, the possibility of inter-racial children have been more prevalent and was rising until the early 2000’s, since that time world travel has been slightly muted, thus there has been less opportunity for inter-race children, and you guessed it… the temperature has been relatively steady or somewhat falling during that same time period.
While it appears that it can’t get any more simpler than that for proof that inter-race mating causes global warming, the author of the study notes that we shouldn’t jump to any conclusions quite yet and that additional funding and studies are needed to help quantify the impact on the planet in regards to global climate change.
Can I has grant to do proper study now?

Are midgets and basketball players different species?
Unless the researchers can show that the hybrids are sterile, or have some other similar hybrid trait, I think the notion that the mating sharks are separate species needs to be rethought.

I was curious about this when I saw it yesterday, so I did some reading about the species in question. They are morphologically indistinguishable except through forensic examination of their precaudal vertebrae, with the Australian Blacktip (Carcharinus tilstoni) having 84-91 and the Common Blacktip (C. limbatus) having 94-102. Since their ranges overlap considerably, I can’t really see how anyone is surprised that there is some interbreeding between the populations.
I also ran across a paper from September 2011. It describes a new field species assay test that is fast and inexpensive compared to full mtDNA testing. It claims to have been 100% accurate when used with 160 DNA test samples. If this was the method used to perform the study that discovered the hybrids, I would suggest that the species assay might not be as accurate as it appeared during the validation process.
Either way, the mainstream media certainly jumped the shark on this one.

Bit off-topic, but can anyone remember the postings by Tamino, where he performed some stats on the global temperature to indicate that it wasn’t really diverging from the models, but was still within the error bands? In those posts he also gave a divergence at which he said that you could consider those models broken.
This was several years ago now, and I wanted to check how far down the line we had gone. But I can’t find the reference. Can anyone help me with this?

Why not…
Sunlight reflecting off the coral bleaching has dazzled the sharks vision.
They can no longer tell each other apart.
And…
The acidification of the ocean has also impaired their smell.
I speculate…
The sharks are confused… just like the unnamed scientists and the author of this article.
Blaming it on humans and CO2…. is crap.

When I was keeping freshwater tropical fish, the ichthyologists were constantly struggling with the designation of species. If they were later found to interbreed, they just got reclassiified as variants rather than separate species. Seems feasible that two types of black tips exist that can interbreed. Everything is known until something new (like DNA) is added. Then, everything is known. And on and on.
Conclusions are a requirement of studies and you can always jump from one to another using the “possibly maybe but requres more study” maneuver.

The worst part is the logic here. The Australian shark (the one limited to tropical waters) is hybridizibg to the widely spread ‘common’ blacktip, which can tolerate cooler waters. So only the Australian shark is expanding its range, gaining the ability to cope with COOLER waters. How is this an adaptation to cope w global warming???

How do we know shark hybridization has not happened before? They’ve been around for a really long time after all and these two species are closely related anyway. The only way to tell an individual shark is a hybrid is DNA testing. So the “never” as in “never happened before” turns out to be the recent period over which DNA testing has been available and actually used on a representative shark sampling. That’s a kind of limited definition of “never”.

I know the old definition of “species” is taking a hit, but traditionally, it has been: animals who can produce viable offspring who can reproduce. In other words, if you have viable offspring who can maintain the population, they are, by definition, of the same species. They might be different sub-species, there might be genetic differences, but if they can produce fertile offspring, then they have historically been considered the same species.

I would guess that hybridization of the Blacktip sharks has been going on for tens of thousands of years if not longer. No one noticed because no one cared. And I still don’t much care. Am I missing something here?

The concept of “species” is a fuzzy one. Ask any taxonomist. In fact, it’s so much of a human construct that nature often ignores it. Well, actually, nature frequently mocks and throws it in our faces. We use it out of convenience and the exceptions (hybrids) are many.

I also heard Diane Sawyer say something about this being caused by global warming. But, my take on this line: Ovenden speculated that the two species began mating in response to environmental change, as the hybrid blacktips are able to travel further south to cooler waters than the Australian blacktips. is that the species are adapting to cooling not warming, as they can handle cooler, not warmer water.

The longer the warmist propaganda machine continues to paddle this kind of garbage the sooner their doctrine will fail. They are hammering nails in their own coffin.
Great response from WUWT.
Next scam please.

Bernie says:
January 4, 2012 at 3:53 am
Somebody was pimping this story. It would be interesting to find out exactly who it was.
The story is politically motivated to secure funding from a government that is desperate to find any evidence to supports it highly unpopular tax policies. The same government that has made it illegal for any store owner to say that the tax has contributed to price increases.
Oz. Where the government rewards folks for saying what the government wants to hear and penalizes them for saying what the government doesn’t want to hear. Could it be that sharks aren’t the only thing in Oz getting screwed by an imported species?

AW said… “Since these “hybrid” sharks are a recent observation, it stands to reason they didn’t exist 20 years ago, maybe even 10 years ago.”
Viv said… “No, sorry, it only stands to reason that such hybrids have not been observed 10 or 20 years ago.”
I agree Viv. Therefore, it stands to reason that sharks have been hybridizing for many millions of years … we’ve only noticed it now. Regardless, AGW is bogus and not the cause.

elmer says:
January 4, 2012 at 6:44 am
This is why I am a evolution skeptic too, I’m pretty sure a Black Tipped Shark can’t tell the difference between the 2 species.
=======================
I suspect more like the bar is closing, and there aren’t that many sharks of the opposite sex to choose from. Besides which, after thirteen pints, who cares about trivia like species differences.

During the last period of global warming, some 1000 years ago, southern Europe ended up with a lot of blond haired hybrids that persist even today in some local populations.
The Vikings, as their own climate warmed, moved into even warmer climates for some hanky-panky. Could this be the case here? That it is actually the Ozzie sharks acting like Vikings and students on spring break? A quick trip to the warmer climes before coming back home to the cold? Once away from prying eyes, they will mate with pretty much anything.

When I read this article yesterday on Fox News it smelled of BS. I suspect that this is the first time they have found these hibirds because it is the first time they have looked. Around here we find hybrides all the time. eg. our 2 deer species often produce hybrids (white tail and mule deer). I don’t this that this is too uncommon.

Ok, this headline deserves it’s own internet meme.. I’ll start it off:I woke up this morning and couldn’t find my slippers: Signs of Global Warming?My local grocer was sold out of Cinnamon Pop Tarts: Signs of Global Warming?The Cable Company put me on hold for 30 minutes and then hung up on me: Signs of Global Warming?

These shark are VERY closely related and we would be well advise to remember Darwin’s caution that species were more correctly seen as matters of taxonomical convenience than any hardline drawn by Nature. Species grade into one another. The percentage of overall genetic variation (Fst) between these two sharks is a very small 0.042. There is also a possible 3rd blacktop specie swimming these waters. http://www.publish.csiro.au/?paper=MF09151
The Australian and common blacktip contrary to the impression given in the press releases overlap in almost equal numbers in northern Australian waters.
What we seem to have here are two fish populations rather than two distinct species. (Although not up on shark details) There are any number of fish species that continue to exhibi genetic isolation despite range overlap. This genetic drift implies individuals among the 2 populations are not “freely interbreeding” -but it does not mean that they never interbreed.
We may expect some of the following to be at work with this “hybridization”:
-Distinct populations generally breed with members – with mate “self selection” selection mediated by smell, visual cues and at times spawning period.
-Assortative mating (where one population is larger than the other) can select against interbreeding
-Alee effect can increase the chance of interbreeding among the populations when mate selection becomes difficult as the result of over-fishing or range expansion.
Temperature would not be the first thing I would look at here. The common blacktip’s number have been significantly decreased as a result of the trade in shark fins- my first instinct would be an alee effect -not temperature. My second is this is much more common than we realize.

For crying out loud! Just because sharks have a body plane that goes back 500 million years does not mean that this is an ancient family. As I have said before, most extant fishes INCLUDING sharks are modern in every sense of the word. The sharks in question here are species of a very important family, Carcharhinidae. This family appeared in the Eocene!

Haven’t we, as a species, spent more time on the moon that we have at the bottom of the ocean?
Don’t scientists say there are MILLIONS of species yet to be discovered?
Somebody needs to post a good picture “The Fonz” on water-skis.

That’s quite a proof of global warming. Couldn’t they have proved a dangerous global warming by the same argument applied to homo sapiens? According to genetic and body size measurements, [SNIP: Lubos, that is not really appropriate. -REP], which may prove that the Earth will be fried by 2020.

There is excellent evidence polar bears are breeding with grizzlies. In North America there is a genus of plants, sarracenia, whose species all naturally hybridize into viable offspring.Hybridization is very common in nature.
The ‘journalists’ who came up with this article are only demonstrating weak ethics and poor skills.

Hybrid Sharks.
Maybe they run on different kinds of fuel.
Maybe they can eat batteries.
Maybe the dorsal fin is taller to catch more wind.
Maybe they run on natural gas propulsion.
Just some sharks trying to saving the planet.
We are not alone…
The truth is out there…
Climate change sure causes some pretty weird stuff.
God only knows what’s next…
sarc/off.

I haven’t read the paper yet, but I get the impression, that the meristics would place the hybrid individuals in one species or another. It was only through DNA analysis that indications of hybridization was revealed. I’m not really a shark guy, being much more interested in fresh water. But these sharks are important. They belong to a genus with a lot of very closely related species. Some are legendary, e.g. the Bull Sharks. BTW, I seem to remember that the Blacktip sharks are one of the main species used for sharkfin soup, hmmm.

Has anyone ever looked for hybrid sharks before?
The ability to do genetic testing on hundreds (thousands?) of sharks isn’t exactly something that’s been around for a century. Just because the technology to detect something exists and is used to detect something for the first time does not mean its the first time its happened.
In other words, I’m guessing sharks have been interbreeding for millions of years and this is the first time humans noticed.

Alan Watt says:
January 4, 2012 at 6:38 am
How do we know shark hybridization has not happened before? They’ve been around for a really long time after all and these two species are closely related anyway. The only way to tell an individual shark is a hybrid is DNA testing. So the “never” as in “never happened before” turns out to be the recent period over which DNA testing has been available and actually used on a representative shark sampling. That’s a kind of limited definition of “never”.
========================
Good point, Alan, I thought the same thing when I read the real press release. We have just begun to use DNA mapping to investigate species and their relationships to each other. I am sure there are many more surprising discoveries to be made as data are accumulated. And, I said it here first, they are ALL caused by global warming! Bwahahahaha!

These sharks have been jumped from two directions. As you so aptly point out, the media have jumped on shouting ‘global warming’ when there is nothing in the story to indicate this was involved at all. But prior to that, the marine biologists jumped on shouting ‘hybridization’ when the simple existence of viable crosses between the two populations supports the idea that these are two *races* of sharks within the same species.
The ability to produce fertile offspring is a satisfactory functional definition of ‘species’ for population biology.

Desert Yote,
“BTW, I seem to remember that the Blacktip sharks are one of the main species used for sharkfin soup, hmmm.”
See my comment above this can cause the alee effect with the commercially harvested common blacktips searching for mates.

So just what is the Physics behind Temperature induced cross breeding. Anybody got any ideas how many base pair switches occur per deg C rise in lower tropospheric Temperatures.
Does this mean that humans from tropical Eritrea might now be able to crossbreed with humans from Siberia or northern Scandinavia.
How much ocean Temperature rise is necessary for sharks to cross breed with porpoises ?
My theory is that the rising popularity of shark fin soup has made it more difficult to see whether that shark over there is a black tip or a white tip, so the sharks are simply confused about who they fraternize with.

Quite comman with cetaceanshttp://marinebio.org/oceans/dolphins.asp
“Three dolphins were found beached on the coast of Ireland in 1933 and were reportedly hybrids between Risso’s and bottlenose dolphins. This mating was apparently later repeated in captivity producing a hybrid calf. A bottlenose dolphin and a rough-toothed dolphin in captivity were also reported to have produced hybrid offspring.”

It is the inter-species breeding between sharks and humans that I worry about. There are far too many “land sharks” preying on our fellow humans. It is these ravenous critters, that I warn my daughter about. Ocean shark’s sexual preference is not by choice, but by an appealing cut of the fin and a flash of belly. Nothing at all to do with remote climate change. Ocean sharks have limited choices, which both start with an “F”. Feed or F**K. GK

Biology . the major subdivision of a genus or subgenus, regarded as the basic category of biological classification, composed of related individuals that resemble one another, are able to breed among themselves, but are not able to breed with members of another species.

If they are interbreeding they are NOT different species. They are subspecies varieties (what in human terms would be called “races”). So for all you “hybrids” out there, just know that the environmentalists find you very alarming. How did you get here anyway? Climate change? Bad. Very bad.

Specieization has been fading for a long time. Now with modern gentics we can determine
interbreeding and range. Now what used to be a color phase,is now a subspieces, or a separate
speices. Everything from squirrels to sharks…

@ AndyG55; you are forcing me to respond. I read an article a few years back regarding the “red wolf”. It seems that after the reintroduction program for the “red wolf” began, a researcher began DNA testing and matching, and found that the “red wolf” is most likely a cross (I resist the term hybrid here because that implies the result is infertile, and the “red wolf” clearly is not) of the gray wolf and a coyote, and not a unique species at all! And the hysteria over the spotted owl is dying down as researchers have come to realize the barred and spotted owls are just different “races”, so to speak, of the same species. And after all, the crossing of the two owls seems to be insuring the spotted owls have descendents, isn’t that a good thing? So, back to the “hybrid” black-tipped sharks: are these “hybrids” fertile? Especially when bred to another “hybrid”? Then, as pointed out by other commenters, this is not a hybrid at all. I tend to agree with the other comment, they didn’t find these hybrids 20 years ago only because the technology was not available to identify them. When they are that plentiful, I suspect they may have always existed.
P.S. If liberals truly believed in evolution, they would allow endangered species to go extinct.

crosspatch says:
January 4, 2012 at 1:45 am
These sharks aren’t even different species, they are simply different varieties of the same species. Using their logic, should a European Caucasian man marry a Japanese Asian woman, we would have some environmental crisis induced inter-species … something … going on.
Give me a break.
Ah, Fred. Go back to the original article. They are same genus: Carcharhinus, but are classed as different species: “tilstoni” vs. “limbatus .” The problem with “species” is that the criteria that are used to delineate a difference at the species level very fuzzy. Ideally, a species is a population that is closed genetically – exchanges genes only among its members rather like climate scientists – but reality wasn’t organized according to ideals. There are examples among modern “species” where the only actual separation is behavioural, that is the difference is really “social” rather than biological or genetic.

Cyrus P. Stell, P.E., CEM
January 4, 2012 at 12:12 pm
###
The red wolf story is far more complicated then what you imply. That you are still parroting 20 year old misinformation just goes to show how badly politics has muddied science. The red wolf is indeed a species and not a mix. The early DNA analysis problem was caused by the wolf DNA reference. The baseline included Timber Wolves. It turns out that Timber Wolves ( C. lycaon) and Red Wolves are varieties of the same US native species which is more closely related to the coyote (C latrans) then either is to the Grey Wolf (C. lupus) which is of Eurasian (Beringia) origin.

This is a normal part of the nature of any species. If a species is closely related of course they are going to interbreed it is all a part of nature’s evolution. Just like the Mule Deer and the White Tail deer have been interbreeding for a long time. Previous generations of hunters have noted that these deer chose to interbreed. So like the 2 species of Black tip, they chose to interbreed, it doesn’t mean global warming or anything like that. It just means that nature takes care of itself, and we have nothing to do with it! Man is so vain, it thinks it can control nature, by giving such a species a name and then noting that they never seen interbreeding of such sharks before? Which century do they live in? I thought that they were scientists, this should have been discovered a long time ago. If the main stream media is going to link it to global warming/climate change then there really is an agenda because why won’t they publish other stories that defy that man has been causing the changes when it is everything that nature is causing the changes. Nature is big on change, she changes all the time and we (MAN) CANNOT CONTROL those changes. We have to let nature take it’s course to see which way our temps will swing.

….hmmm, couldn’t we use this convergence of the two shark species as a proxy for approximating the climate at the original evolutionary divergence…and wouldn’t that climate be similar to the current climate…?

Talk about jumping the shark. More wild and indiscrimate fish sex coming:
“Met Office 2012 annual global temperature forecast
4 January 2012 – 2012 is expected to be around 0.48 °C warmer than the long-term (1961-1990) global average of 14.0 °C, with a predicted likely range of between 0.34 °C and 0.62 °C, according to the Met Office annual global temperature forecast.”http://www.metoffice.gov.uk/news/releases/archive/2011/2012-global-temperature-forecast

DesertYote says:
January 4, 2012 at 12:38 pm
“It turns out that Timber Wolves ( C. lycaon) and Red Wolves are varieties of the same US native species which is more closely related to the coyote (C latrans) then either is to the Grey Wolf (C. lupus) which is of Eurasian (Beringia) origin.”
This is news to me and I keep up on this. Please provide a link or your source on this.
I hope you understand that some DNA analyses done by the eco-crisis industry is as reliable as Mike Mann’s work on climate history. So as this scenario you describe makes zero sense to me I need to see where it came from. Thanks.

Al Gored
January 4, 2012 at 1:01 pm
###
The eco-nut have lately been trying to keep this quite. The reclassification of C. rufus would remove them from the endangered species list, which they do not want. Yet they are torn. The reclassification of C. lupus lycaon as C. lycaon would help justify using the Timber Wolf as a more formidable political weapon. Of course the genetics seems to indicate that the Red Wolf and all of the Timber Wolves are just inter grades, none of which are endangered.
I am at work, but when I get home, I will try to dig up a reference for you. I seem to remember that Meech wrote a paper a few years back that was pretty good science. I tend to judge him a bit harshly because of some of the nonsense that issues for from his mouth, but this paper looked very solid.

I cannot find any evidence that these two sharks are in any way separated by a temperature gradient. Both these sharks do well in both tropical and semitropical waters. They seem to perfectly overlap in their geographic range within Australian waters. They were considered the same species up until 1980.
All the Australian blacktips are a single population but not so with the more worldly common blacktip.
These two sharks are nearly identical except for some small genetics and form a closely related clade. The only visual difference is the larger size of the common blacktip (no help when dealing with subadults) and one having a propensity of more vertebrates before the tail. So these hybrids would and could only be seen by highly trained experts.
Fish have an amazing ability to selectively breed not only true to their own species ( whatever the definition) but also among their own sub-population. We can see this at work in some river lake systems with dozens of genetically isolated breeding populations of sockeye salmon co-existing within the same river system. The mate selection “barriers” that lead to isolated breeding include kin recognition by odor, and visual cues (size and other often small morphological cues)
The question is why are two distinct shark breeding populations -that normally overlap in geographic range- now interbreeding? The first and most obvious possibility is that they always have and that with the increased availability/cost of DNA testing we are just now noticing these “hybrids”. Given that these sharks have a maximum life of around twenty years and the pictures shown in the press of the hybrids are adults we start pressing back towards the date when no-one believed a hybrid was possible- seeing them all as a single specie!
Even so there is some question as to why we are seeing hybridization of isolated breeding populations as the Australian blacktips certainly seem to be. As I wrote earlier the alee effect seems to be the most likely explanation- IF the number of hybrids is outside of the normal anticipated range. And that I do not know.
My first thought if the number of hybrids is indeed anomalous then we are seeing an alee effect. Most likely the result of the crash in common blacktop numbers being targets as they are for the shark fin fishing fleet. The Common blacktop reduced in numbers has insufficient mates which then breaks down the visual and kairomone odor cues allowing breeding with Australians. It would be interesting to know which species were the females producing the hybrids.
I just cannot see how this is or could be in any way temperature related.

OK Yote. I’ll check back. But I must say, I don’t believe it – for many reasons – and I can see why the eco-crisis industry would want to tell that story.
That said, I don’t accept the idea of the ‘red wolf’ as a real species in any case – and I know one of the Chief Liars involved in this garbage, and more – so I get your point about it.
These people have been faking DNA stuff for a long time now, and it is very difficult to double check their results. Sometimes it is so obvious that it is laughable, like the so called ‘Sacramento Red Fox.’

The WashPo carried this today but put it on the Politics page along side of “Far below, new species emerge” apparently recognizing both as more political than scientific although the second doesn’t appear to have an attached political statement.

Tom Davidson said @ January 4, 2012 at 10:48 am
“The ability to produce fertile offspring is a satisfactory functional definition of ‘species’ for population biology.”
Herring gulls are spread from western Europe, across the whole width of Asia and across North America to the east coast. Each adjacent colony can breed with an adjacent colony, but the colonies of the American east coast and western Europe are mutually infertile and therefore by your definition different species.
Species are a “good faith guess” Quoting a Pompous Git:
There is, in fact, to use Sterelny and Griffiths’ words, a flock of species concepts:
* Phenetic species concepts define species by appealing to the intrinsic similarities between organisms. The idea is to purge species identification of theoretical commitments.
* Biological species concepts define species by appealing to reproductive isolation. One version of the biological species concept is the recognition concept, which defines species as systems of mate recognition.
* Cohesion species concepts generalise the biological species concept by recognising that gene flow is not the only factor that holds one population together and makes it recognisably different from others.
* Ecological species concepts define species by appealing to the fact that members of species are in competition with one another, since they need the same resources.
* Phylogenetic and evolutionary species concepts define species as segments of the tree of life. A species is a lineage of organisms, distinguished from other lineages by its distinctive evolutionary trajectory, and bounded in time by its origin in a speciation event and its disappearance by further speciation, or extinction.
[From Sterelny and Griffiths Sex and Death p 193]
It would be surprising indeed if all of these disparate ways that biologists view species produced agreement on which organisms were members of which species.

As others have noted, what constitutes a (separate) species is nothing like as clear as many think.
When there is interbreeding across part of the range of two apparently separate species, they are generally considered sub-species.
This may also be an example of a cline.
Clines consist of ecotypes or forms of species that exhibit gradual phenotypic and/or genetic differences over a geographical area, typically as a result of environmental heterogeneity. Genetically, clines result from the change of allele frequencies within the gene pool of the group of taxa in question.[2][3][4] Clines may manifest in time and/or space. (from wikipedia)

Greg Cavanagh said @ January 4, 2012 at 1:33 pm
“I hear that bacteria contain human DNA. Does that mean they are human?”
It seems ever more likely that bacteria (prokaryotes) carry all of the DNA of all of the eukaryotes.

WUWT: ‘I suspect this was the trigger for the reporter jumping the shark:
“Hybridisation could enable the sharks to adapt to environmental change…”‘
And since the Aus blacktip shark wasn’t even restricted to tropical waters but ranged into cooler southern waters without the need to “hybridize,” we now know that the scientists got it wrong on that count too. Nice catch.
In summary…sharks find eachother attractive and Aussies have PM Julia Gillard, and a carbon tax, all still inexplicable. Future study needed.

I agree with Philip Bradley @ January 4, 2012 at 1:46 pm. This might be an example of a cline . A cline is one of the more interesting aspects of biology, and the most interesting example of a cline is the ring species.

Due to Climate Change at the end of the Roman Warm Period, the Red-Headed Northern Homo Sapiens moved south and interbred with the Northern European Homo Sapiens, creating cross-species hybrids that are still present today.
After surviving the next mini-ice-age, these cross breeds traveled widely during the Medieval Warm Period, producing further cross-species breeding with Homo Sapiens in the Mediterranean and on the North and South American continents.
Later, these crossbreeds started plantations in the southern part of North America, and they imported Negroid Homo Sapiens from Africa. This led to more crossbreeding between the species.
Next, these crossbred mutants wanted to build a railroad across the United States (a hotbed of crossbreeds) and so they imported many Chinese Homo Sapiens to work on the railroad, and of course, crossbreeding occurred.
These evil crossbreeds are the creators of the huge increase in CO2 which is driving Climate Change.
According to the latest Environmental Reactionary Press Releases, Climate Change drives crossbreeding of species that should never have occurred.
If we don’t stop the Australian Black Tipped Shark from breeding with the Common Black Tipped Shark, they will eventually join man in creating more CO2 than they would have, and thus drive Global Warming even faster to the brink of Earth’s destruction.
We must immediately build ice plants to make enough ice to cool the ocean enouch to keep the Australian Black Tipped Shark from breeding with the Common Black Tipped Shark! If we don’t, all Sharkdom is doomed!
/sarc ! ! ! !

‘”It’s very surprising because no one’s ever seen shark hybrids before, this is not a common occurrence by any stretch of the imagination,” Morgan, from the University of Queensland, told AFP.’
Then we get this mysterious addition:
‘”This is evolution in action.”‘
Really? I’d call it sex.
I’d never have though that sex between a horse and a donkey producing a mule was
“evolution in action.” Everything is AGW everything is evolution… everything is everything.
sigh…

Philip Mulholland says:
January 4, 2012 at 2:32 pm
I agree with Philip Bradley @ January 4, 2012 at 1:46 pm. This might be an example of a cline . A cline is one of the more interesting aspects of biology, and the most interesting example of a cline is the ring species.
I’m not sure how this is a cline as the Australian blacktips almost completely overlaps the Australian range of the common blacktip. In fact over most of this range the population split between Australian and common is 50:50.

First we are told animals won’t be able to adapt to AGW, then they claim this shark is quickly adapting to AGW. Once again, they want it both ways.
I guess really this should weaken the AGW scare because apparently species can and will adapt… so why worry?

Responding to the 2 Phils and Pat re: clines.
Clinal variation is the gradual change in a trait or traits over a recognized environmental gradient, and is usually referring to variation within a single species. An excellent example is balsam fir and the clinal variation exhibited by cone bracts. In the southern Appalachians on the highest mountain tops, the tree is known as Fraser fir, and for a while was known taxonomically as Abies fraseri. Now known as A. balsamea var. fraseri. The cone bracts of Fraser fir extend well beyond the cone scales, giving the cones a feathery appearance.
As one moves north along the Appalachian Mountain range, balsam fir grades into A. balsamea var intermedia, or intermediate fir. Here the cone bracts are much shortened, but still extend beyond the cone scales.
Finally, true balsam fir (A. balsamea, var balsamea) in New England and eastern Canada, the cones appear completely smooth – the bracts are totally enclosed by the cone scales. If one were to take samples of each fir from each part of the range, the variation would be discontinuous, suggesting 3 species. However, sampling stands close together in space, there would be non-significant differences in bract length, suggesting a single species with clinal variation.

I’m inclined to agree with PPs that it’s a cline. It may be that individuals at the extreme geographic boundaries (north and south) of this cline have difficulty interbreeding, but the ones with overlapping habitat have probably been doing it for ever.
Taxonomy wars are every bit (if not more) bitter than climate change wars. As an Australian orchid enthusiast, I have had some of my pet orchids renamed 3 times in 30 years. Fortunately, the orchids don’t seem to mind. What’s more, some of them cross-pollinate naturally in the most libidinous fashion in my garden (presumably under cover of darkness) despite what the books say. I think it demonstrates the low level of scientific literacy among orchids.

Philip Mulholland says:
Pat
OK. Just might be, but not certainly.
Then again, remember that the ocean is three dimensional 🙂
They both inhabit shelf water and about the same range of depths (3rd dimension?).

Philip Foster said @ January 4, 2012 at 3:28 pm
‘”I’d never have though that sex between a horse and a donkey producing a mule was
“evolution in action.” Everything is AGW everything is evolution… everything is everything.
sigh…”
And herring gulls from the American east coast are not the same species as those from western Europe and they are the same species. Welcome to the Wonderful World of Post-modernism.

I did the obvious thing this morning and emailed Jessica Morgan the following:
From: Dennis Kuzara [mailto:xxxxxxxxxx]
Sent: Thursday, 5 January 2012 1:04 AM
To: jessica.morgan@uq.edu.au
Subject: Is this quote accurate?
Jessica
Dina Spector of the Business Insider,| Jan. 3, 2012, 3:09 PM, stated the following:
> The world’s first hybrid shark was discovered by scientists in waters off Australia’s east coast on Tuesday, reports Amy Coopes of the AFP.
>
> According to lead researcher Jess Morgan, the hybridization might be a sign that the animals are adapting to rising temperature levels as a result of climate change.
The press release made no mention of “climate change” or “global warming”. Is the quote in this news article that is attributed to Jess Morgan, (which I assume is Jessica Morgan) accurate?
Since sea surface temperatures have increased less than 0.45 degree C over the last 30 years, clarification of any known ties between shark interbreeding and climate change would be appreciated.
Thank you
Dennis Kuzara
And I received this reply:
On 1/4/2012 7:34 PM, Morgan, Jessica wrote:
Quote not correct – I have now stated numerous times that it is extremely unlikely that climate change caused the hybridization event – however, the hybrid-Australian blacktips are now being seen further south of their known range (Australain blacktips have a tropical distribution) in cooler waters suggesting that the hybrids may have a wider temperature tolerance than their parents (ie the hybrids may be better adapted to handle changing water temperatures). That long statement is being condensed and printed as your quote below.
Jess
I will now ask Dina Spector why she misquoted Jess

Dennis Kuzara quoted Jess, Morgan:
“Quote not correct – I have now stated numerous times that it is extremely unlikely that climate change caused the hybridization event – however, the hybrid-Australian blacktips are now being seen further south of their known range…”
Wowsers! Hybrid vigour — who’da thunk it?

The sent time on the email to Jessica Morgan was 10:04AM EST Jan 4, 2012, but what I printed out from the reply was the Australian time (when she received it).
According to Jessica, the sharks are now being seen in in cooler waters, which is the opposite of the reporter’s “suggestion”.
In any case, the discussion here has little to do with sharks and a lot to do with media bias and reporters who inject their own biases into their reporting. When it is found that a reporter misrepresents the fact, they should be called out on it.

If it can happen in water it should be happening on land as well. I expect to see sightings of new species any day now. My first guess is some kind of Polar Bear/Penguin hybrid; I’m assuming one of them has enough for the airfare.

Dennis Kuzara says:
“however, the hybrid-Australian blacktips are now being seen further south of their known range (Australain blacktips have a tropical distribution)”
The explanation given to you by Jessica Morgan does not seem to fit with the most recent research (2010) by Boomer et al. that shows the Australian blacktip’s range is not confined to the tropics but extends well into temperate waters.http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.2010.02770.x/abstract
I don’t see how even the hybrid range extension claimed by Morgan holds up.

Huffington Post also didn’t bother to go to the source before printing this story:http://www.huffingtonpost.com/2012/01/03/hybrid-sharks-australia-coast_n_1181491.html
Sad, they only went as far as the Australian Broadcasting Corp for their version of the story.
What is interesting to me is this hybridization may be the shark’s response to increased predation of sharks by humans. This is leading to various ecological niches forming where some breeds of sharks have been over hunted, and these holes are now being filled by the hybrids.

“SNIP: Lubos, that is not really appropriate. -REP”
It’s not “appropriate” because it’s normal in the society not to look at these things rationally: and this clearly doesn’t apply to climate alarmists only. In reality, the reasons why genetically sufficiently distant individuals crossbreed are completely analogous for humans and sharks. It just happens, there’s no law that could prevent it.
So as long as we view these things rationally and as long as we find it OK to intervene into the two shark parents’ intimate privacy, we should be able to understand that doing the same thing with the major homo sapiens example is the same thing. But that’s not how these things are being treated, as the censorship above shows as well. These silly taboos are really the primary reason why people are so eager to believe various anthropocentric, anthropomorphic, and anthropogenic theories of natural phenomena.
People are led to think that humans play a qualitatively different role in Nature even in respects in which they’re clearly just another species.

The “Species Barrier” is more like a “species strong suggestion”. I go into it in some depth in a comment here:http://chiefio.wordpress.com/2011/12/27/open-talk-tuesday-5/#comment-28532
but the short form is that there are A LOT of hybrids between species and many are fertile. The “species do not interbreed” is a useful shortcut taught in high school, kind of like Newtonian Mechanics, Useful, but incomplete and not always correct.
See:http://en.wikipedia.org/wiki/Triangle_of_U
for the THREE different species with different chromosome counts that cross to make the SIX different broad groups of brassicas. Cabbages, kale, turnips, mustards, etc.http://en.wikipedia.org/wiki/Toast_of_Botswana
has an interesting example with sheep / goats with sporadic fertile offspring.http://en.wikipedia.org/wiki/Hybrid_%28biology%29
lists a whole lot more (including one of my favorites, the Zonkey… looks like a Donkey with zebra striped socks on 😉
BTW, humans have a different chromosome count than our Chimp-like ancestor. We merged two chromosomes IIRC. That means the first “human” had to cross back with a different chromosome count mate, then stabilize the cross by repeated culling. (like one would do with the sheep/goat cross if desired).
Species cross rather more often than most folks think and WE would not exist if you could not have sporadic crossing even with different chromosome counts.
The shark story ought to say: “Absolutely normal sex happened and nothing of interest”.
Now if they had different numbers of chromosomes and were strongly isolated species, it would be much more interesting; but still quite normal.

Tom Davidson says:
January 4, 2012 at 10:48 am
“These sharks have been jumped from two directions. As you so aptly point out, the media have jumped on shouting ‘global warming’ when there is nothing in the story to indicate this was involved at all. But prior to that, the marine biologists jumped on shouting ‘hybridization’ when the simple existence of viable crosses between the two populations supports the idea that these are two *races* of sharks within the same species.”
He said *races* He’s a racist!!!! Shock!! Horror!!!
BTW, I can guess what Lubos (sorry, I don’t know how to do the accent in Ubuntu) wrote, and suspect it was amusing. Pity about the prudery of Americans.

Curiousgeorge says:
“Do sharks practice safe sex? Is there a shark body shop some where in the area?”
or maybe a brothel ???
E.M.Smith says:
“Now if they had different numbers of chromosomes and were strongly isolated species, it would be much more interesting;”
You aren’t from New Zealand are you ?? (Aussie joke about sheep and New Zealanders)

So clearly, this new hybrid is a recent decadal scale development, and the last ten years of temperature in the area have been essentially flat. Connecting this with “global warming” doesn’t wash.
I disagree. This “new” hybrid is probably as ancient as the hills. Hybridization is actually not that uncommon among all sorts of animal species that are closely similar and that share a common range — the article exaggerates this, I fear, in implication but note well the real conclusion:flagged a warning that other closely related shark and ray species around the world may be doing the same thing.
“Wild hybrids are usually hard to find, so detecting hybrids and their offspring is extraordinary,” Dr Ovenden said.
Yes, lots of closely related species all over the planet may, and probably are, doing the same thing, and probably have been doing it far more commonly than we have long believed. Hybridization is one of the things that can possibly explain the extreme rapidity with which evolution can happen — variability within a species is clearly not as great as the variability accessible between species.
As for “hard to find” — if two species with common ancestors have mostly non-overlapping physical habitat — which is often the case, given that enough genetic drift has occurred for them to be considered different species, an observation that goes all the way back to Darwin and the finches of the Galapagos, then they simply lack the opportunity to interbreed. Sharks, however, experience no “barriers”, and there is no range of the Australian coastline where there are no blacktips. We can safely assume that their ranges have always overlapped by tens to hundreds of miles — there is no “magic temperature” in the ocean that repels sharks of one or the other species (and their territorial cues may not be temperature at all, it might be particular kinds of food. Who is really surprised by this? I’m not. It is evolution in action. Given enough hybrids that the hybrids themselves start to breed amongst themselves (perhaps driven by an “advantage” — hybrid vigor), and a bit of selection pressure, and a third species may emerge in between the two that are there now, and may expand into both of the older ranges. That’s what evolution does!
The “difficulty” at detecting wild hybrids is also very easy to explain. It was all but impossible to do at all until roughly 25-30 years ago. The extraordinary progress that has been made in genetics has been triggered by discoveries that are still remarkably recent — e.g. PCR, the ability to take genes out and amplify them — plus a remarkable array of physical equipment. We are still far, far from done mapping out the genotype of all of the world’s species — lots of genes, and lots of species. I wouldn’t doubt that this is the work this team is engaged in — mapping out the genotypes — so that they naturally enough would be the ones to observe and discover the hybridization.
Or, perhaps they discovered a new species, one in the process of emerging from hybridization. That would be really cool, because there is another debate I often participate in, and that is the debate between the numb-nuts who claim that the Earth is only ~6000 years old and that God hand-made all of the species. Evidence of evolution in action is marvelous stuff, although — in a way strangely like the debate over climate — simple evidence is never enough to convince a True Believer.
It is amazing how this original report was twisted into “proof” of global warming, though. An injudicious choice of words in the original report (there doesn’t have to be an environmental shift to cause two species with no physical barrier between them to have a common/overlapping range — it is expected that they will, this was something that didn’t need an explanation) is transformed by the alchemy of Faith into proof of global warming rather than proof of a dynamical ecosystem.
Really, they should look at birds. Birds, like fish, usually have ranges defined more by habit and competition than by climate. In the US, for example, there are similar species of songbirds with heavily overlapping ranges that hybridize, but really, this happens all of the time, all over the world, between all sorts of “neighboring” species. Hybrid offspring are often, but not at all always, sterile with both parent species (“mules”). The “not always” is well known to breeders of domesticated animals, who sometimes crossbreed a domestic species with a nearby wild one to try to fix some desired trait from the wild species in the domestic population. What humans do, nature does.
Anyone interested can read the wikipedia article on “Hybrid (biology)” — it is really quite interesting as it gives the lie to the idea that there is some sort of magic repellent that keeps similar species apart. While hybridization is usually between two animals in the same genus — the red wolf is believed to be a hybrid species produced by natural crossbreeding between wolves and coyotes, for example, sometimes, species that are very different manage to produce offspring. To quote from this article: “Where there are two closely related species living in the same area, less than 1 in 1000 individuals are likely to be hybrids because animals rarely choose a mate from a different species (otherwise species boundaries would completely break down). In some closely related species there are recognized “hybrid zones”.”
As I said, this happens all the time. It is not rare, it is commonplace. It is just the first observation of the phenomenon in sharks, and it is far more likely the case that it just hasn’t been observed because it hasn’t been looked for carefully enough than it is a “new” thing caused by humans.
The article clearly points out that humans are an important factor in hybridization. Indeed, we are probably the most important fact by an order of magnitude at this point, because we are constantly destroying or disrupting habitat or are simply actively moving species between different continents and then letting them go. See “killer bees”, kudzu, zebra mussels, and many more examples of our meddling and its sometimes profound effects on the environment. However, “climate change” a) happens all of the time without our help, and species either respond to it or fail the Darwinian test; b) is way, way down the list of things that threaten the purity or survival of species.
To put it bluntly, it is perhaps 10x more likely that if some anthropogenic rearrangement of the natural ranges of the sharks has occurred, it has occurred because of something other than climate change. For example, overfishing the waters so a key food species for one or the other becomes rare, driving the species further afield looking for food. Pollution causing blooms of toxic algae, ditto. Simple overfishing of the shark species themselves. Pressure on their breeding grounds. I teach every summer in one of the breeding ranges of blacktips (different species) I’m sure and several other (closely related but fairly “rare”) East Coast sharks — “spinner” sharks, for example. I fish for the same fish that they eat, and I not infrequently catch baby blacktips or baby spinners. I wouldn’t be at all surprised if hybridization is taking place right outside my summertime door, but there is so much that is not known about shark breeding and what its cues are and where/how it occurs that it might be a decade before anyone finds out and/or works out plausible reasons it is occurring.
rgb

@ DesertYote
I refer you to the following: http://www.canids.org/PUBLICAT/CNDNEWS3/2conserv.htm Note that there is no mention whatsoever of a timber wolf species, all North American wolves are called gray wolves, other than the “red wolf”. And yes, I do notice that the date on the reference is from 1995, but that’s still less than the 20 years you claimed. (My brother got out of a speeding ticket with a similar argument: The ticket said he was doing 65 in a 55. The attorney asked my brother, “How fast were you going?” “I thought it was more like 75 myself.” Ticket dismissed, the officer failed to prove my brother was doing 65. So, specious (almost a bad pun, idn’t it?) as it may be, if I prove you wrong on one point…)

@ DesertYotehttp://genome.cshlp.org/content/21/8/1294 with a publication date of May 12, 2011. Recent. And reaffirms my original point. And in case you missed my original point, the fact that we develop a new technology that can observe something previously unobservable does not make it a new phenomenon. I suggest the shark species cross always existed, and probably always will, there’s nothing humans could or even should do about it.

Oops, sorry E. M. Smith — I missed your more or less identical remarks before posting. My bad. Truly a case (we agree) of “Move along, folks, nothing to see here”.
I almost brought up your observation about humans and chimps (and gorillas) because it is one of the most compelling pieces of evidence for evolution of both species from a common ancestor. Humans have 46 chromosomes; chimps have 48. Chromosome 2 (in humans) is clearly composed of a fusion of two chimp chromosomes. The evidence for this isn’t ambiguous — it is certain — you can see it for yourself here:http://science.kqed.org/quest/2008/05/12/chromosome-fusion-chance-or-design/
Look at the near identity, slot by slot, for chromosome 2. Pretty amazing, actually. I sometimes wonder if “Yetis” and “Bigfoot” (if they exist) are human-whatever hybrids. Humans are well known for breeding well outside of their species lines (and sometimes halfway across the animal kingdom). There is a funny story in my family about how, in the early days of the Internet, my sister in law was trying to find the hours a nearby petting zoo was open by using (IIRC Alta Vista), a Google precursor. This was in the days of modem connection, quite slow, so she typed in “zoo farm” or some such and clicked the first link she got, with her (very small) kids looking over her shoulder.
Imagine, my friends, a picture, slowly emerging on the screen a few lines at a time. An elephant — good, it is a zoo! A woman’s face. Aw, look at that, she must be a zookeeper and the elephant likes her! The lines inexorably fill in, lower and lower and — yeep! That woman doesn’t have any clothes on! And what is that elephant doing with its trunk! Exeunt in haste, come on kids, nothing to see here, we’ll use the yellow pages, Rooobbbb (I was the resident “computer expert”) come in here and make that picture go away…
Human-chimp, human-gorilla, human-orangutan wouldn’t surprise me at all. Human-horse wouldn’t surprise me that much — I seem to recall some Russian Tsarina who was (shall we say) overly fond of horses. Give anything enough opportunities, some pretty unlikely surprises can occur in breeding…;-)
But we digress…
rgb

Cyrus P. Stell, P.E., CEM
January 5, 2012 at 6:54 am
###
I was not disputing that hybridization happens naturally, and that new tools are revealing more cases for it. Your understanding of North American canids is quite incomplete. The Coyote x Grey Wolf theory for the Red wolf has been around for well over 20 year. The east coast wolves were originally considered a separate species ( C. lycaon (Linneus)) with the common name of Timber Wolf. That was revised to C. lupus lycaon, when naturalist started to encounter Grey Wolves (C. lupus), like they had in Europe. The Red wolf was different enough that they considered it a separate species (C. rufus). Early DNA testing included Timber Wolf and Grey wolf DNA as the Wolf reference. Of course the results would indicate that the Red Wolf shared DNA of Coyote ( C. latrans (say)). The Wolf DNA basis was invalid.
Your 1995 reference is way too old. Resent studies (e.g. Wilson 2002), on both morphology and DNA ( BTW, DNA analysis is no panacea) has shown that both C. lupus lycaon and C. rufus are the same species that ranged all across the eastern North America along the Appalachian range. This species is the sister of C. latrans and a North American native. That means that C. rufus is a coyote relative and only looks wolf-like because of adaption.
Personally I prefer to let the Marxist be the experts in perverting science to serve political ends. As Heinlein wrote “One can not use the weapons of the devil to defeat the devil”.

@Robert Brown..
“Imagine, my friends, a picture, slowly emerging on the screen a few lines at a time. An elephant — good, it is a zoo! A woman’s face. Aw, look at that, she must be a zookeeper and the elephant likes her! The lines inexorably fill in, lower and lower and — yeep! That woman doesn’t have any clothes on! And what is that elephant doing with its trunk!”
Man do you need some education re interbreeding ! 😉
Hint: The trunk ain’t gunna do nothing in that regard !!!!

DesertYote says:
January 5, 2012 at 10:04 am
Thanks for those links. Due to time constraints I can’t spend much time on this until later but there are things that do not make any sense whatsoever, and things you are missing.
First, the original classifications of North American wolf subspecies by Merriam (like his classification of about 90 SPECIES of grizzly (brown) bears) was completely bogus.
Second, the original range of coyotes did not extend as far east as the so-called Red Wolf.
Third, what is a dog? When millions of Native North Americans living in eastern North America died of smallpox, what happened to all their ‘dogs’?
Finally, even if it was done with complete honesty, any recent DNA analysis is dubious at best because of historic population bottlenecks and the mixture of wolves and ‘dogs’ for the past two (plus) centuries, compounded more recently by the eastward expansion of coyotes .
The so called hybrization between wolves and ‘dogs’ – SAME species – is a very large and complex story which the green gang obviously would not want to think about. But I think it explains the so called ‘Red Wolf.’
On the subject of ‘wolf’ subspecies, it is worth noting that the same liars are promoting the absurd concept that the wolves on the BC coast – which no historic observer ever recorded, and which are not isolated from interior pops – are some unique subspecies to ‘save.’ No surprise. Each new ‘subspecies’ is like a franchise for the ‘species at risk’ listing industry if they can fool people into accepting them.

Al Gored
January 5, 2012 at 12:52 pm
###
What is really funny is that many canid specialist are doubting the validity/utility of most subspecies designations for canids in general, and C. lupus in particular, yet the greenies are still trying to make every sub-population a subspecies. I am among those who think the whole idea of subspecies is flawed except in a very few cases (C. lupus baileyi, maybe). Merriam is guilty of crimes against taxonomy.
BTW, the Marxists definitely do not like the idea of invalidating C. rufus. If the red wolf ends up being C. lycaon, then the legal basis, under the ESA, for all of the control of private property that they currently enjoy, by evoking the endangered listing of C. rufus, goes out the window, even faster then if it is found that the population was formed from hybridization.
I am, like you, puzzled and dismayed by the lack of research on the North American dogs and the impact that they most surely have had. When I was a kid (I have always been a canid nut) I wanted to know about the dogs that the Indians had. No one knew anything. WOW how could that be?

Desert Yote
The topic of Indian ‘dogs’ is one that would be tooooo inconvenient for popular green mythology.
Tis a huge subject so, again due to time constraints, may as well leave it at that for the time being, except for one comment… that is, that ironically, both sides of the western wolf reintroduction issue have their heads in the sand on wolf ‘subspecies’ and all that. The people against those reintroductions like to argue that the reintroduced wolves, from Alberta, were the wrong subspecies. So for that argument they need to cling to the the old ‘splitter’ taxonomy.
So much fuzzy ‘science’ whenever political issues are involved.

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